Dry ice refrigeration apparatus



March 9, 1965 A. R. DuBois ETAL 3,172,271

DRY ICE REFRIGERATION APPARATUS March 9, 1965 A. R. DuBois ETAL 3,172,271

DRY ICE REFRIGERATION APPARATUS Filed June 1o, 196s s sheets-sheer 2 E l Q 4 67 @fg/63 ,65 l `Zzzzzzmzm 66 79 w 49 70 I 69 73 o f 60 1 l LQ i (72 7/ 74/ 76 I@ o 75., f *62 62a; 77 INVENTORS 75, 59 JAMES VAN\ J6 BY A RENE DuBoxs March 9, 1965 A. R. DUBols ETAL DRY ICE REFRIGERATION APPARATUS 3 Sheets-Sheet 3 Filed June lO 1963 INVENTORS JAMES VAN\ BY A. RENE DUBOB 77 /WR/I M# HIL-271:15.

United States Patent O 3,172,271 DRY ICE REFRIGERATION APPARATUS Albert Ren Dubois, Chicago, and .lames Vani, ridlothan, Ill., assignors to Controiled Heat Transfer Corporation, Chieage, lll., a corporation of Iiiineis Filed June 10, 1963, Ser. No. 286,610 12 Claims. (Ci. 62-16S) This invention relates to refrigeration apparatus and more particularly to refrigeration apparatus of the type which is particularly well adapted for use in trucks, refrigerator cars, holds of ships, and the like.

It is a primary object of the present invention to afford a novel refrigeration apparatus.

Refrigeration apparatus for use in trucks, railroad cars, holds of ships, and the like, have been heretofore known in the art. However, such refrigeration apparatus as has been heretofore known has commonly had several inherent disadvantages such as, for example, being large and bulky in size; requiring expensive compressor units; being difficult to service and maintain; not being constructed so as to effectively withstand the bumps and stresses to which such apparatus is subjected when installed in moving vehicles, vessels, and the like; or not being practical and ei-cient in operation, and the like. It is an important object of the present invention to overcome such disadvantages.

Another object is to afford a novel refrigeration apparatus of the aforementioned type wherein the temperature of the space to be refrigerated may be accurately controlled.

Another object is to afford a novel refrigeration apparatus of the aforementioned type wherein refrigerant ows therethrough in a closed circuit, and the tiow of the refrigerant is controlled in a novel and expeditious manner.

An object ancillary to the foregoing is to afford a novel valve for so controlling the flow of such refrigerant.

A further object is to afford a novel refrigeration apparatus of the aforementioned type wherein the cooling of the refrigeration liquid may be effected by a suitable solid refrigerating medium such as, for example, solidified carbon dioxide, commonly known as Dry Ice.

Another object is to afford a novel refrigeration apparatus of the aforementioned type wherein the controls for controlling the flow of refrigeration liquid are actuated in a novel and expeditious manner by the pressure of the gas formed from the solid refrigerating medium.

Yet another object is to afford a novel refrigeration apparatus of the aforementioned type which is relatively small and compact in size, and yet affords a relatively large cooling capacity.

Another object is to afford a novel refrigeration apparatus of the aforementioned type which is strong in construction and reliable in operation.

A further object is to afford a novel refrigeration apparatus of the aforementioned type which may be readily serviced and maintained.

Another object is to afford a novel refrigeration apparatus of the aforementioned type which is practical and efficient in operation, and which may be readily and economically produced commercially.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by way of illustration, show a preferred embodiment of the present invention and the principles thereof and what we now consider to be the best mode in which We have contemplated applying these principles. Other 3,172,271 Patented Mar. 9, 1965 ICC embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims.

In the drawings:

FIG. l is a fragmentary sectional view of a refrigeration apparatus embodying the principles of the present invention, showing the apparatus disposed in operative position in a cold storage housing;

FIG. 2 is an enlarged sectional View taken substantially along the line 2-2 in FIG. 1;

FIG. 3 is an enlarged detail sectional View taken substantially along the line 3 3 in FIG. l;

FG. 4 is a somewhat diagrammatic view of the temperature control unit shown in FIG. l;

FIG. 5 is a fragmentary view of a portion of the control unit shown in FIG. 4, with certain parts disposed in different operative position; and

FIG. 6 is a fragmentary diagrammatic view of the refrigeration apparatus shown in FIG. 1.

A refrigeration apparatus 1 embodying the principles of the present invention is shown in the drawings to illustrate the preferred embodiment of the invention.

The refrigeration apparatusV 1 is shownin FIG. 1 mounted in a substantially rectangular-shaped cold storage housing 2 in position to refrigerate the space within the housing 2. The refrigeration apparatus 1 is particularly well adapted for use in trucks, railroad cars, holds of ships, and the like. However, if desired, the refrigeration apparatus 1 may also be used in stationary refrigeration rooms, storage rooms, and the like. Therefore, it will be understood by those skilled in the art that the housing 2 may be any suitable type of cold storage housing, including the trailer portion of a refrigerator truck, a refrigerator car, the hold of a ship, or a stationary cold storage room, and the like.

The refrigeration apparatus 1 embodies, in general a primary heat exchanger 3 and a secondary or ultimate heat exchanger 4 with the primary exchanger 3 feeding a suitable refrigerant liquid such as, for example, methylene chloride, to and through the secondary heat exchanger 4 in a closedrcircuit therewith, and with the secondary heat exchanger 4 being mounted. in the `cold storage chamber 5 in the housing 2 in position to effectively cool the latter. Y l

The housing 2, embodying the storage chamber 5 to be cooled, includes a front wall 5, a rear wall 7, a top wall 8, a bottom wall 9, and two oppositely disposed, substantially parallel side wallsrlti and 11, FIG. l. The housing 2 normally embodies an access opening, not shown, in the rear wall 7, to afford access to the storage chamber 5, the opening being normally closed by a door, not

shown.

The primary heat exchanger 3 includes an elongated substantially lrectangular-shaped housing 12 extending laterally across the upper front portion of the storage chamber 5. The housing 12 is mounted on suitable supporting members 101V and is secured to the top wall 8 of the housing 2 by suitable means such as bolts 102. It includes an outer shell 13 made of suitable material such as, for example sheet steel or sheet aluminum, and a bunker or component 14 is mounted in the housing 12 for holding a supply of suitable refrigerating material, such as, for example, the aforementioned Dry Ice. 'Ihe bunker 14 includes an elongated, substantially cylindricalshaped main body portion 15 which extends transversely across the housing 2. A substantially cylindrical-shaped duct 16 extends forwardly from the longitudinal central portion of the main body portion 15 outwardly through the front wall 6 of the housing 2 to afford an access 'opening into the bunker 14. The front end of therduct 16 is normally closed by a pressure-tight door 17 removably mounted therein. With this construction the bunker 15 may be readily loaded with blocks of Dry Ice, r the like, from outside of the housing 2, by removing the door 17, inserting the blocks of Dry Ice 1S through the duct 16 into the main body portion 15 into position such as that shown in FIG. 1, and then reinserting the door 17 in position to close the front end of the duct.

An elongated reservoir 19 for suitable refrigerant liquid such as, for example, the aforementioned methylene chloride is disposed in the housing 12 in good heat exchange relation to the main body portion of the bunker 14. The reservoir 19 is substantially annular in transverse cross-section, and includes a substantially cylindrical-shaped outer shell portion 20 mounted in the housing 12 in surrounding, outwardly spaced relation to the main body portion 15 of the bunker 14. The outer shell 20 is deformed substantially radially outwardly at the upper portion thereof to afford a substantially rectangular-shaped reserve tank 21`extending the length thereof. The inner wall 'of the reservoir 19 is afforded by the main body portion 15 ofthe bunker 14. VThe bunker 14 is preferably made of a suitable sheet material having high conductive properties, such as, for example, sheet aluminum, to afford good heat exchange relationship between the interior of the bunker and the interior of the reservoir 19. Suitable insulation material 12a is mounted in the housing 12 around the reservoir 19 to retardldirect heat transfer between the reservoir 19 and the storage chamber 5, to thereby prevent excessive localized cooling of the storage chamber 5 in the area immediately surrounding the reservoir 19.

An outlet conduit or cold side conduit 22, including a down pipe 23 and an outlet manifold 24, is connected to the lower portion of the reservoir 19, the down pipe 23 being connected at its upper end to the bottom of the reservoir 19, and at its lower end to the front end of the outlet manifold 24. The 'outlet manifold 24 extends rearwardly along the bottom wall 9 of the housing 2 from the down pipe 2.3 for substantially the entire length of the housing 2, for a purpose which will be discussed in greater detail presently. The 'outlet manifold preferably is mounted on and supported by a wooden strip 25 on the upper face of the bottom wall 9, and is preferably secured thereto by suitable means such as brackets 26, FIG. 1.

An inlet Aconduit or warm side conduit 27 is also connected to the reservoir 19. The inlet conduit 27 includes an inlet manifold 28 connected to the upper end portion of the reservoir 19 disposed adjacent to the side wall 10 of the housing 2 substantially at the junction of the bottom ofthe reserve tank 21 with the main body portion of Vthe reservoir 19, and extends rearwardly therefrom in closely adjacent relation to the top wall 8 of the housing 2 substantially the entire length of the latter, for a purpose which will be discussed in greater detail presently. The inlet manifold 28 is preferably `secured to the side wall 10 of the housing 2 by suitable means such as mounting brackets 29, FIG. 1.

The secondary heat exchanger 4 includes a plurality of substantially rectangular-shaped heat exchanger panels 30 secured by suitable means such as bolts 31 to the side wall 10 of the housing 2 in upstanding position between the outlet manifold 24 and the inlet manifold 28. The heat `exchanger panels 30 are all identical to each other, and each includes two side panels 32 and 33 se- .cured to each other along the peripheral edge portions 30a thereof by suitable means, such as, for example, welding. The panels 32 and 33 are preferably formed from a material having good heat conductive properties, such as, for example, sheet aluminum which is anodized to impart a black color thereto. Each of the heat exchanger panels 30 is hollow, the sheets 32 and 33 being convex outwardly between the marginal edge portions 3ta thereof. Two inwardly projecting ribs 34 and 35 are formed in each of the sheets 32 and 33 on respective sides of the longitudinal center line thereof, in relatively closely adjacent relation to each other. The lower ends of the ribs 34 and 35 are disposed in upwardly spaced relation to the lower marginal edge portions 30a of the sheets 32 and 33 and are interconnected at their upper ends by respective ribs 36 disposed in downwardly spaced relation to the upper edge portions 30a of the respective sheets 32 and 33. The ribs 34-36 on the sheets 32 and 33 are disposed in such position that when the sheets 32 and 33 of a heat exchanger panel 30 are disposed in operative position relative to each other, the ribs 34-36 of each of the sheets 32 and 33 are dis'- posed in abutting engagement with the corresponding ribs of the other one of the sheets 32 and 33, to thereby denne a chamber 37 in the panel 30' which is open at the bottom and closed at the top for a purpose which will be discussed in greater detail presently.

Other channels 3S which are open both at the bottom and at the top thereof are similarly defined by ribs 39 formed in the sheets 32 and 33 in parallel spaced relation to each other and to the ribs 34 and 35, on opposite sides of the latter. Corresponding ribs 39 on the sheets 32 and 33 of each assembled panel 30 are disposed in abutting engagement to each other so that the channels 38 afford conduits extending longitudinally of the panels 30.

The heat exchanger panels 30 are secured to the side wall 1i) of the housing 2 in parallel spaced relation to each other, and, as will be discussed in greater detail presently, in the operation of the refrigeration apparatus v1. refrigerant liquid passes through the panels 3i! for cooling the chamber 5 in the housing 2. The panels 30 are preferably disposed closely adjacent to 'each other and are sufficient in number that they extend substantially the entire length of the housing 2 from the primary heat 'exchanger to the rear wall 7, so as to afford a substantially constant temperature along the side wall 10 throughout the length of the chamber 5. Preferably, the panels 30 are disposed at an angle of approximately 15 degrees to the vertical so that refrigeration liquid tends to impinge against the ribs 39 during the now of the liquid upwardly through the channels 38.

The lower end portion of each of the heat exchanger panels 30 is connected to the outlet manifold 24 by a suitable conduit such as a pipe 40, the rearwardmost panel 3Q being so connected to the rear end of the manifold 24. Similarly, the upper end portion of the heat exchanger panels 30 is connected to the inlet manifold 28 by a suitable conduit, such as a pi'pe 41, ythe rearwardmost panel 30 being so connected to the rear end of the manifold 23.

A normally open control valve 42 is mounted in the down pipe 23 of the outlet 'conduit 22 for controlling the tiow of refrigeration liquid therethrough. A check valve 43, which is of the type operable to permit flow of liquid through the inlet manifold 27 toward the reservoir 19, is mounted in the manifold 28. With this construction, during a refrigeratin'g operation, refrigeration liquid may ow from the bottom of the reservoir 19 downwardly through the down pipe 23, rearwardly through the outlet manifold 24, upwardly through the heat exchanger panels 30, and forwardly through the inlet manifold 28 back to the upper portion of the reservoir 19, the liquid reacting to convection forces 'caused by changes in density of the liquid to therebyV cause this circulation of the liquid. Y

A tiller tube 19a is connected to the reserve tank 21 and extends forwardly therefrom through the front wall V6 of the housing 2. A vent tube 1917 extends upwardly from the top of the reserve tank 21 through the top wall v8 of the housing 2. The vtubes 19a -a-nd 19b are normally closed by suitable means such as caps 44. A bleeder valve 28a is mounted on the -top of the inlet manifold 28. When it is desired to till the reservoir 19 and the liquid circulating system connected thereto with refrigeration liquid, the caps 44 may be removed from the tubes 19a and 19h and the bleeder valve 28a may be opened. The liquid may then be poured into the reservoir 19 through the liller tube 19a. When the reservoir 19 and the liquid circulating system are filled to the desired level with the liquid, the caps 44 may be replaced on the tubes 19a and 19h and the bleeder valve 28a may be closed, to thereby seal the system.

It will be remembered that in the operation of the refrigeration apparatus 1 the bunker 14 is charged with Dry Ice. As is well known to those skilled in the art, unless solid carbon dioxide is maintained under relatively high pressure, it changes to its gaseous state, and under normal temperature conditions is capable of producing relatively high pressures within a container in which it may be sealed. In the novel refrigeration apparatus 1 the pressure created by the Dry Ice 1S in the bunker 14 is utilized to actuate the control valve 42, as will be discussed in greater detail presently. For this purpose, and also for the purpose of venting the bunker 14 so as to prevent the buildup of excessively high pressures therein, as will be discussed in greater detail presently, one end of a conduit 45 is connected to the upper portion of the bunker 14 and extends downwardly and forwardly therefrom through the front wall 6 of the housing 2. The other end of the conduit 45 is connected to the inlet port of a pressure regulator 46. One outlet port of the pressure regulator 46 is connected by -a conduit 47, a manually operable shut-oif valve 48, and a conduit 49 to one port 49a of a three-way valve 50 of a temperature control unit 51, FIGS. 1 and 4. A safety valve 52 is connected to the conduit 45 between the pressure regulator 46 and the bunker 14 to limit the maximum pressure of the gas within the bunker 14. In refrigeration systems used in vehicles, vessels, and the like, the maximum pressure which is permissible in bunkers, and the like, is commonly controlled by regulations established by the controlling authorities. The safety valve 52 is of the type which will release and vent the conduit 45 to atmosphere if the pressure within the bunker 14 exceeds the permissible pressure therefor, such as, for example, pounds per square inch. The pressure regulator 46, in addition to the outlet connected to the conduit 47, has another outlet to which a conduit 53 is connected, FIG. 4, for venting the bunker 14 to atmosphere. The pressure regulator 46 is of the type that when the pressure in the conduit 45 is below a predetermined pressure, such as, for example 18 pounds per square inch, the connection' to the conduit 53 is closed, but when the pressure in the conduit 45 exceeds the aforementioned pressure, the pressure regulator is effective to open the connection to the conduit 53 and thereby-vent the conduit 45, and, threfore, the bunker 14 to atmosphere. Preferably, the outlet end of the conduit 53 opens into the storage chamber 5 of the housing 2, so that the cool-ing effect afforded by the gas ven-ted from the conduit 53 is utilized in the chamber 5. The-chamber 5, of course, is not hermetically sealed so that no pressure buildup is effected therein by the venting of the gas from the conduit 53 thereinto.

The normally open valve 42 includes a housing 81 having a lower portion 82 and an upper portion 83 secured together by suitable means such as bol-ts 91, FIG. 3. A resilient diaphragm 84-extends across the housing S1 between the portions 82 and 83, to thereby afford a pressure chamber 85 in the upper portion 83 of the housing 81. The lower portion 82 of the housing 81 has an opening 86 extending through the lower portion'thereof, and the opening 86 is closed by a resilient diaphragm 87 disposed in substantially parallel spaced relation to the diaphragm 84. An actuating member 88 extends between diaphragm 84 and 87 in such position that movement of the diaphragm 84 downwardly, and movement of the diaphragm 87 upwardly, from the normal, substantially horizontally extending positions thereof, is effective to correspondingly move the other diaphragm 87 and 84, respectively.

The control valve 42 also includes an inlet 89 and an outlet 90 connected into the down pipe 23.v A substantially annular valve seat 54 is disposed between the inlet 89 and the outlet 90, and refrigeration liquid passing through the valve 42 passes from the inlet 89 to the outlet 90 through the valve seat 54. A valve member 55 is disposed between the diaphragm 87 and the valve seat 54 in position to move upwardly and downwardly with the diaphragm 87 out of and into sealing engagement with the valve seat 54, to thereby open and close the connection between the inlet 89 and the outlet 9). A compression coil spring 56 is disposed in the valve 42 in position to normally yieldingly hold the valve member in upwardly disposed position, to thereby normally maintain the outlet 90 and the inlet 89 in communication with each other. Y

One end of a conduit 57 is connected to the upper portion 83v of the valve housing 82 above the diaphragm 84, FIGS. 1 and 3, and the other end portion of the conduit 57 is connected to one port 58 of the valve 50, FIG. 4. The other port 59 of the valve 50 is an exhaust port to atmosphere. The valve 50 includes a valve plate 60 disposed in overlying relation to the ports 49a, 58 and 59. The plate 60 has a substantially L-shaped recess 61 formed in the lower face thereof in such position that when the valve plate 60 is disposed in the position shown in FIG. 4, the long leg 62 of the recess 61 interconnects the ports 49a and 58, and the recess 61 is out of communication with the portV 59 to thereby close the latter. Under these conditions, it will be seen that the pressure chamber 85 of the valve 42 is connected through the conduit 57, the port 58 of the valve 50, the recess 61, and the port 49a to the pressure line or conduit 49 to thereby feed gas from the bunker 14 into the chamber 85. When gas is so fed from the bunker 14, the pressure in the chamber 85 is effective to deflect the diaphragm 84 downwardly into position to movethevalve member 59 into engagement with the seatv54 against the urging of the spring 56, and thereby close the down pipe 23 of the outlet conduit 22.

The recess 61 is so disposed in the valve plate 60 that when the plate 60 is disposed in the position shown in FIG. 5, the short leg 62a interconnects the ports 58 and 59, and the recess 61 is out of communication with the port 49a to thereby close the latter. Under these conditions, the pressure chamber 85 of the valve 42 is vented through the conduit 57, the port 58 of the valve 50, the recess 61, and the port 59 to atmosphere. When the chamber 85 is so Vented to atmosphere the diaphragms 84 and 87 of the valve 42 are disposed in the horizontally extending position shown in FIG. 3, so that the valve member 55 is held inopen position by the spring 56 and refrigeration liquid is permitted to ow through the outlet conduit 22.

In the refrigeration apparatus 1 shown in the drawings, the valve 50 of the temperature control unit 51 is controlled by a control mechanism 63, which includes a temperature sensitive control bulb 64 of a type well known to those skilled in the art. The control bulb 64 may be mounted in any suitable location in the chamber 5 in the housing 2, for sensing the Vtemperature in the chamber 5. 'I'he control mechanism 63 includes a cylinder 65 having a piston 66 reciprocably mounted therein. The bulb 64 is connected by a suitable conduit 67 to one end 68 of the cylinder 65, and the piston 66 has a piston rod 69 extending outwardly through the other end 70 of the cylinder 65 into abutting engagement with the intermediate portion of a lever 71. One end of the lever 71 is pivotally mounted on a pin 72, and the other end is pivotally connected by a pin 73 to one end of a link 74. The other end of the link 74 is pivotally connected by a pin 75 to the free end of an arm 76 extending outwardly from the valve plate 60, so that oscillation of the lever 71 around the pin 72 is effective to move the plate 60 around a center post 77, between the positions shown Vin FIGS. 4 and 5. The arm 76 extends outwardly through a slot '78 in the valve 50 and is movable therein between positions shown in FIGS. 4 and 5 A tension coil spring 79 is connected to the lever 71 between the pin 72 and connecting rod 69 in position to urge the lever 71 to rotate in a counterclockwise direction, as viewed in FIG. 4, to thereby urge the piston 66 upwardly in the cylinder 65. Thus, when the temperature inthe chamber 5 is at or below the temperature for which the control unit 51 is set, the spring 79 is effective to hold the lever 71 in the raised position shown in FIG. 4 and thereby hold the valve plate 6) in the postion shown in FIG. 4 wherein the ports 49a and 58 are in communication with each other to thereby pressurize the chamber 85 of the valve 42 and close the latter and thus prevent the flow of additional refrigerant liquid through the secondary heat exchanger 4. When the temperature in the chamber 5 rises above the temperature, which the temperature control unit 51 is set to maintain, the gas in the bulb64 expands to force the piston 65 downwardly and thereby pivot the lever 71 in a clockwise direction around the pin 72 from the position shown in FIG. 4 to a position effective to move the valve plate 60 into the position shown in FIG. 5, wherein the ports 58 and 59 are interconnected to thereby vent the chamber 85 of the valve 42 to atmosphere and thus permit the valve 42 to open and permit refrigerant liquid to again flow to the secondary heat exchanger 4 and thereby cool the chamber 5. It will be remembered that each of the heat exchanger panels 3) has a downwardly opening chamber 37, which is closed at the top, extending along the longitudinal center line thereof. When refrigerant liquid is inthe panels 3,0 it moves upwardly into the chambers 37 thereof. However, the air trapped by the liquid in the upper portion of the chambers 37 prevents the liquid from completely filling the latter. Hence, a cushion of air is always present in the upper portions of the chambers 37.- These cushions of air act somewhat as shock absorbers for the panels 30, when the latter are subjected to shocks or bumps, such as, for example, when a truck in which the panels are mounted strikes a bump in the road. Without such cushions, such shocks to the panels 30 cause the liquid therein to be moved against the marginal edge portions of the panels 30 with sufficient force that in some instances panels have been known to burst. It has been found that by providing the chambers 37 in the panels 30, the air cushions afforded thereby are effective to take up enough of such a shock to the liquid as'to prevent the bursting of the panels 30 under normal conditions.

In addition to the panels 30 of the secondary heat exchanger 4 mounted along the wall 10, a plurality of other panels, which are identical thereto, are similarly mounted along the inner face of the wall 11 of the housing 2. These other panels mounted along the wallY 11 are connected to the reservoir 19 in the same manner as the panels 30, and these other panels and the parts connecting the same to the reservoir 19 are indicated in FIG. 6

by the same reference numerals as the correspondingV parts heretofore described, with the prefix 1 added thereto. Thus, it will be seen that: the outlet conduit 122 includes the down pipe 23 with the control valve 42 mounted therein, and an outlet manifold 124; the outlet manifold 124 is connected to the lower ends of the eat exchanger panels 130, by suitable conduitsV 140; the upper ends of the heat exchanger panels 130 are connected by suitable conduits 141 to the inlet manifold 128 of the inlet conduit 127; and the inlet conduit 127 has a check valve 123 and bleeder valve 128a therein and is connected to the end of the reservoir 19 remote from the inlet conduit 27.

In the operation of the refrigeration apparatus 1, the bunker 14 is rst charged with a suitable refrigeration medium such as the Dry Ice 18 and the door 17 is then closed. While the temperature in the cold storage chamber 5 remains above the temperature at which the control unit 51 is set, the control bulb 64 is effective to hold the piston 66 in the control mechanism 63, FIG. 4, in lowered position to thereby dispose the valve plate 60 in the position shown in FIG. 5 and thereby vent the chamber S5 of the valve 42 to atmosphere through the'conduit 57 and the ports 58 and 59 of the valve 50. This permits the valve 42 to be held in open position by the Vspring 56 and thereby permit refrigeration liquid to flow by convection downwardly from the reservoir 19 through the pipe 23 and the outlet manifold 24, upwardly through the heat exchange panels 30, and back to the upper portion of the reservoir 19 through the inlet conduit 27. The flow of refrigerant' through the panels 30 is effective to cool the cold storage chamber 5.

When the temperature in the cold storage chamber 5 is at or below the temperature for which the control unit is set, the gas in the temperature sensitive control bulb 64 is ineffective to hold the piston 66 in downward position against the urging of the spring 79, and the spring 79 is effective to rotate the lever 71 into the position shown in FIG. 4, wherein the valve plate 6G is disposed in position to interconnect the ports 49a and 58 in the valve 50. This is effective to permit the pressurized gas to flow from the bunker 14 through the conduits 45 and 49, the ports 49a and 58 of the valve 50 in the control unit S1, and the conduit 57 Vinto the chamber 85 of the valve 42 remains closed no further refrigerant liquid is fed and close the valve 42. Closure of the valve 42 is effective to prevent further flow of refrigerant liquid from the reser voir 19 downwardly through the pipe 23, so that while the valve 42 remains closed no further refrigerant liquid is fed into the panels 30. When the temperature in the cold storage chamber 5 again rises above the temperature at which the control unit 51 is set, the gas in the control bulb 64 is again effective to actuate the valve into position to again open the valve 42 and thereby cause refrigerantV liquid to again be circulated from the bottom of the reservoir 19 upwardly through the panels 30 and back to the upper portion of the reservoir 19.

With the refrigeration apparatus 1 constructed in the Y aforementioned manner, it is capable of efficiently refrigerating4 a cold storage chamber, and maintaining the temperature within such a chamber substantially constant. Tests have shown that the refrigeration apparatus constructed in accordance with the principles of the present invention is effective to maintain the temperature in such a storage chamber lon a truck trailer within one degree of the desired temperature throughout trips of several hundred miles.

Also, it will be seen that the present invention affords a novel refrigeration apparatus which is particularly well adapted for use in refrigerator trailers, refrigerator cars, and the like.

In addition, it will be seen that the present invention affords a novel refrigeration apparatus wherein the operation thereof is controlled in a novel and expeditious manner.

Thus,'while we have illustrated and described the preferred embodiment of our invention, it is to be understood that this is capable of variation and modification, and we therefore do not wish to be limited to the precise details set forth, but desire to avail ourselves of such changes and alterations as fall within the purview of the following claims.

We claim:

1. Refrigeration apparatus comprising (a) primary heat exchange means including (l) a reservoir for refrigeration liquid, and

pressurized means and to said valve means and re- .t

sponsive to the pressure in said pressurized means for actuating said valve means, and (f) temperature responsive means for sensing the temperature in said space and operatively connected to said connector means for controlling the operation of the latter. 2. Refrigeration apparatus as defined in claim 1, and in which (a) said pressurized means includes a compartment disposed in heat exchange relation to said reservoir and adapted to hold a gas under pressure. 3. Refrigeration apparatus as defined in claim 2, and in which (a) said reservoir is elongated and of substantially annular transverse cross-section, and is disposed around said compartment in substantially horizontally extending position, and

(b) said conduit means are connected to the top and bottom of said reservoir for circulating such liquid outwardly from the bottom of said reservoir and back into the top thereof by convection.

' 4. Refrigeration apparatus comprising` (a) primary heat exchange means including (l) a reservoir for refrigeration liquid, and

(2) means including a pressurized compartment having gas under pressure therein, for cooling said liquid,

(b) ultimate heat exchange means for cooling a space to be cooled and including (l) a heat exchanger panel,

(c) conduit means for feeding said refrigeration liquid from said reservoir to said panel and back to said reservoir,

(d) valve means in said conduit means for controlling the ow of said liquid from said reservoir to said panel,

(e) pressure responsive means operatively connected to said valve means for opening and closing the latter,

(f) additional means, including other valve means, op-

eratively connected to said pressure responsive means and to said compartment and operable to permit and prevent the feeding of said gas from said compartment to said pressure responsive means to thereby control the pressurization of said pressure responsive means, and

(g) temperature sensitive means operatively connected to said additional means and adapted to be mounted in such a space for controlling said operation of said additional means in accordance with the tempera ture inl said space.

5. Refrigeration apparatus comprising (a) primary heat exchange means including (l) a reservoir for refrigeration liquid, and (2) means, including a compartment in heat exchange relationship to said reservoir, for cooling said refrigeration liquid in said reservoir, (b) said compartment being adapted to hold a gas under pressure therein, (c) ultimate heat exchange means adapted to be mounted in a space to be cooled for cooling said space,

(d) means for circulating said liquid from said reservoir to said ultimate heat exchange means and back to said reservoir in a closed circuit for cooling said ultimate heat exchange means, and

(e) means for controlling said circulation of liquid,

(f) said last-mentioned means including (l) valve means operable to open and close said means for circulating liquid,

(2) other valve means operatively connected toV said first-mentioned valve means and said compartment for feeding such gas to said first-mentioned valve means for actuating the latter, and (3) temperature responsive means :operatively connected to said other valve means and adapted to be mounted in said space for controlling said other valve means and thereby controlling the operation of said first-mentioned valve means in accordance with the temperature in said space. 6. Refrigeration apparatus for cooling a storage space comprising (a) a bunker for holding a supply of solid and gaseous carbon dioxide under pressure,

(b) a reservoir of substantially annular transverse cross-section disposed around said bunker for holding a supply of refrigeration liquid in heat exchange relationship to said bunker,

(c) an outlet conduit connected to the bottom of said reservoir for feeding such liquid therefrom,

(d) an inlet conduit connected to the top of said reservoir for feeding said liquid thereto,

(e) heat exchanger panels adapted to be mounted in such a storage space and operatively connected between said conduits for feeding said liquid from said outlet conduit to said inlet conduit and thereby cool said storage space,

(f) a valve in said outlet conduit for controlling the flow of said liquid therethrough, and

(g) means for opening said valve when the temperature in such a storage space is above a predetermined temperature and closing said valve when the temperature in such a storage space is below said predetermined temperature,

(h) said means including (l) another valve operatively connected to said bunker and to said first-mentioned valve for feeding such gaseous carbon dioxide from said bunker to said first-mentioned valve for actuating the latter, and

(2) temperature sensitive means adapted to be mounted in such a storage space and operatively connected to said other valve for controlling the latter in accordance with the temperature in said storage space.

'7. A refrigeration apparatus as defined in claim 6, and

which includes (a) valve means connected between said other valve and said bunker for controlling the pressure of such gaseous carbon dioxide in said bunker.

8. A refrigeration apparatus as defined in claim 6, and

which includes (a) a pressure regulator connected between said other valve and said bunker for controlling the pressure at said other valve.

9. A refrigeration apparatus as defined in claim S, and

in which (a) said pressure regulator includes an exhaust conduit for feeding such gaseous carbon dioxide into such a storage space when the pressure in said bunker exceeds a predetermined pressure.

10. A refrigeration apparatus as defined in claim 6,

and in which (a) said first-mentioned valve includes (l) a chamber for receiving such gaseous carbon dioxide,

(2) a diaphragm (a) extending across said chamber and (b) movable between an actuated position and a normal position as the pressure in said chamber rises and falls,

(3) a valve seat through which such liquid may ow when said Erst-mentioned valve is open, and

(4) a valve member movable with said diapljagm into engagement with said valve seat and into spaced relation to said valve seat upon movement of said diaphragm into said actuated positionv and said normal position, respectively, to thereby close and open said tirst-mentioned valve, respectively.

l1. A refrigeration apparatus as defined in claim 10,

and in which (a) said iirst-mentioned valve also includes (l) another diaphragm disposed therein in substantially parallel relation to said first-mentioned diaphragm,

(2) an actuating member disposed between said diaphragms in position to cause said diaphragms to move in unison, and

(3) spring means operatively engaged with said valve member in position to urge said valve member toward said spaced relation to said valve seat,

(b) said other diaphragm is disposed in operative engagement with said valve member on the side thereof remote from said spring means, and

(c) said first-mentioned diaphragm is disposed on the side of said other diaphragm remote from said valve member.

12. In a cold storage chamber,

(a) a bunker mounted in an upper portion thereof holding a supply of solid and gaseous carbon dioxide under pressure,

(b) a reservoir having refrigeration liquid therein mounted around said bunker in heat exchange relation thereto for cooling said liquid,

(c) a plurality of elongated, hollow heat exchanger panels mounted along two opposite sides of said chamber in upstanding position,

(d) said panels being disposed below the top of said reservoir and extending below the bottom thereof,

(e) cold side conduit means interconnecting the bottom of said reservoir to the bottom of said panels for feeding said liquid from said reservoir into said panels,

(f) warm side conduit means interconnecting the top or" said reservoir to the top of said panels for returning said liquid from said panels to said reservoir, and

(g) means for controlling the flow of said liquid through said cold side conduit means and thereby controlling the ow of said liquid through said panels and said Warm side conduit means,

(h) said means for controlling the flow of liquid including (l) a normally open valve in said cold side conduit means,

(2) means, including another valve, operatively connected to said bunker and to said tirst-mentioned valve for feeding said carbon dioxide gas from said bunker to said rst-mentioned valve for closing the latter, and

(3') temperature sensitive means mounted in said chamber and operatively connected to said other valve for opening and closing the latter upon lowering and raising of the temperature in said chamber, respectively, below and above a predetermined temperature.

References Cited by the Examiner UNITE-D STATES PATENTS ROBERT A. OLEARY, Primary Examiner.

Attest:

UNITED STATES PATENT OFFICE CERTIFICATE 'OF CORRECTION Paten; No. 3,172,271 'March 9, 1965 Albert V-R'e'n Dubois al. i lt is hereby certified *Elin-aff, error appears v'in' Jalle above numbered vafc.- ent req-.lrng Corre-ation and that the said Letters Patent should read as oorreotedbelow. v A 1 4 Column 8, line 34., strike out "remins olosed no :furtherv refrigerant liquid is fed" vandinser'fcv instead to thereby.v deflect the diaphragm 84 downwardly Signed and sealed thisv A24th dey lof Aug-u-S't' (SEAL) l EDWARD J. BRENNER Commissioner of Patents"` 

1. REFRIGERATION APPARATUS COMPRISING (A) PRIMARY HEAT EXCHANGE MEANS INCLUDING (1) A RESERVOIR FOR REFRIGERATION LIQUID, AND (2) PRESSURIZED MEANS FOR COOLING SAID LIQUID, (B) ULTIMATE HEAT EXCHANGE MEANS FOR COOLING A SPACE TO BE COOLED AND INCLUDING (1) A HEAT EXCHANGER PANEL, (C) CONDUIT MEANS FOR FEEDING SAID REFRIGERATION LIQUID FROM SAID RESERVOIR TO SAID PANEL AND BACK TO SAID RESERVOIR, THE INTERIORS OF SAID CONDUIT MEANS AND SAID RESERVOIR BEING SEALED FROM SAID PRESSURIZED MEANS AT ALL TIMES, (D) VALVE MEANS IN SAID CONDUIT MEANS FOR CONTROLLING THE FLOW OF SAID LIQUID FROM SAID RESERVOIR TO SAID PANEL, 